The low FODMAP diet has been shown to be effective in reducing symptoms of IBS in anywhere from 50-85% of individuals studied, however, the diet can be contraindicated (e.g. not a good idea!) in a variety of scenarios. Although the structured three-phase diet (Elimination, Reintroduction, Personalization) is a powerful tool in helping IBS sufferers identify which specific foods trigger daily gut symptoms, it can also be challenging to follow or a bit of “overkill” for some individuals with mild intolerances. It can also be downright problematic for people who have pre-existing nutritional deficiencies or a pattern of disordered eating. This article will discuss alternatives to the “full-blown” low FODMAP diet and who should consider a modified option.
(Note: It is important to discuss your specific health concerns with your doctor and/or dietitian before starting an elimination diet such as the low FODMAP diet. This article does not take the place of professional medical advice).
By design, the low FODMAP diet significantly reduces fiber intake (including fruits, vegetables, and grains) from an individual’s diet temporarily. While careful planning can ensure continued sufficient fiber intake, some individuals with IBS-C may find that their symptoms are exacerbated rather than improved during the elimination phase. Additionally, some individuals diagnosed with IBS-C may be improperly diagnosed, as there are other conditions that can also cause long-term constipation, such as functional constipation or pelvic floor dysfunction. In these latter cases, reducing FODMAPs may not be a significant advantage. Instead, treatments such as medications, fiber supplements, physical activity and/or physiotherapy may be more appropriate and useful.
Nutritionally At-Risk Individuals
Extensive elimination diets are not recommended for individuals who may be at risk for malnutrition or who have certain comorbid conditions in addition to IBS. Due to the significant reduction in dairy products, grains, and certain fruits and vegetables, the elimination phase of the low FODMAP diet is low in certain nutrients, including calcium, vitamin D, iron and prebiotic fiber.
Children are notoriously picky eaters and may risk developing nutritional deficiencies by further limiting their diets. In addition, there are several high growth periods during childhood, including both early childhood and adolescence, where children are growing rapidly and need more nutrients (not less!) than usual. Pregnant women also have increased nutritional needs in order to support a healthy pregnancy and may suffer nutritionally from a restricted diet. Thus, a modified low FODMAP approach that only limits certain foods may be best for most children and pregnant women.
In addition, individuals who may have a weakened immune system (such as individuals with multiple autoimmune disorders or those undergoing chemotherapy for cancer) or impaired nutrient absorption (due to medications, aging, congenital conditions or surgical changes to the gastrointestinal tract) should also pay close attention to their nutrient intake. Careful consideration of the balance between IBS symptom management and nutritional adequacy is critical to maintaining overall health.
Finally, individuals who already follow a limited or restricted diet as a result of medical conditions (e.g. diabetes, epilepsy) or personal choice (e.g. vegetarian, vegan, low carb) should also carefully consider their dietary needs before embarking upon a further restricted diet such as the low FODMAP diet in order to ensure properly balanced nutrition.
Eating Disorders and Cyclic Dieting
There is significant overlap in both the symptoms and the prevalence of functional gut disorders (FGD), such as IBS, and eating disorders (ED), such as anorexia nervosa, bulimia nervosa, binge eating disorder and ARFID (avoidant/restrictive food intake disorder; characterized by extremely selective eating patterns and highly limited numbers of “safe” foods).
Individuals who have restricted their diet or undergone cycles of bingeing and purging over a long period of time will likely suffer from gut symptoms such as constipation, slow digestion or gastroparesis, acid reflux, and related issues. In some cases, these changes to the gut may not be recognized as symptoms of the eating disorder, and the individual may instead seek care for a suspected FGD. It’s important to realize that further restriction of food in such a situation is not only inappropriate, but it can be dangerous both nutritionally and psychologically. Thus, the low FODMAP diet is not a good option for individuals with diagnosed eating disorders, and it is critical that healthcare providers assess patients properly for any history of eating disorders, disordered eating or cyclic dieting before recommending dietary changes.
Simplified Low FODMAP Diet Options & Diet Alternatives
As outlined above, there are a variety of scenarios where the complete three-phase low FODMAP diet (and related attention paid to serving sizes, FODMAP stacking and meal timing) may not be appropriate or downright unhealthy. In these cases, dietitians often recommend a gentler approach. This might include one of the following strategies:
- Reduce Diet-specific FODMAPs. This entails taking a comprehensive dietary history and identifying the foods highest in FODMAPs that are most frequently eaten by that individual. For example, if a child with IBS eats fruit and dairy products four times per day, but doesn’t eat many vegetables or grains, we might recommend reducing just fructose and lactose for several weeks to try to address their symptoms.
- Reduce Common FODMAP Triggers. In clinical practice, the most common foods that trigger IBS symptoms include wheat and rye, garlic and onion, beans and pulses, and dairy products. Thus, for some individuals, the dietitian might recommend reducing or eliminating only these foods temporarily, rather than all high FODMAP foods.
- Alternative Therapies. Dietary change is one avenue for achieving symptom control for IBS sufferers, however, it is far from the only effective strategy. For some individuals, non-food approaches may be more appropriate and effective. For example, gut-directed hypnotherapy and other stress-reduction techniques can be powerful aids. Exercise, medication, and treatment for related anxiety, depression and/or stress are other well-studied and effective treatments for IBS symptoms.
Many dietitians are already using these strategies with positive results with their patients and clients and recognize the need for a flexible approach to the low FODMAP diet.
“The low fodmap diet should be personalized to be the least restrictive needed for symptom relief,” says Audrey Inouye, RD and owner of IBS Nutrition in Edmonton, Canada. “Many people do not need, and should not, take an extreme approach to benefit significantly from this diet. In my practice, I always take current FODMAP intake, medical history, and lifestyle into consideration to personalize the low FODMAP diet. For many people, a gentler, more targeted approach is all they need.”
“The low FODMAP diet is a revolutionary approach for the treatment of IBS, effective in reducing symptoms in up to 85% of individuals when implemented under the close guidance of an experienced dietitian. In at-risk individuals with complex health needs, children or those with a history of disordered eating patterns, it is crucial that they work with a specialist dietitian to develop a tailored treatment plan. In these cases, I work with clients closely to devise a simplified low FODMAP diet in consideration of their medical history, lifestyle and nutritional needs in order to achieve symptom relief with the least amount of dietary restrictions. In my experience, there simply isn’t a one-size-fits-all approach when it comes to IBS.” Charlyn Ooi, Dietitian & Founder of the FODMAP Focus Program.
“Many of us clinicians have instinctively adopted a ‘FODMAP-gentle’ approach based on our assessments of a particular patient’s most likely trigger food(s)–which can sometimes be isolated from a detailed food/symptom history. It’s great to see a broader discussion of when this practice is most appropriate, and how best to implement it.” Tamara Duker Freuman, MS, RD, CDN
The low FODMAP diet is a powerful tool in the IBS treatment toolbox. However, individual nutritional requirements will vary, requiring a personalized and flexible approach to the treatment of IBS. Talk with your doctor and dietitian about which approach(es) may be best for you, your lifestyle and your long-term health.
Diana is a Registered Dietitian who lives part of the year in the tiny country of Luxembourg in Europe and part of the year in Seattle, Washington. She has a private practice that reflects her international background, and she counsels clients with gastrointestinal disorders, food allergies and intolerances, and other nutritional issues.
Diana has completed the Monash University Low FODMAP dietitian’s training and the Advanced FODMAP Training for Dietitians course from Kings College of London. She holds a masters in public health and nutrition from the University of Washington and previously worked in community and public health prior to starting her private practice.
Diana has 3 young children and spends a lot of time driving them around to soccer practice. She loves running, cooking, weightlifting, reading and traveling. And eating!